1. Field of the Invention
This invention relates to oral and dental hygiene preparations containing plaque-preventing quaternary ammonium compounds.
2. Description of the Relevant Art
Oral and dental hygiene preparations are products used to clean and care for the oral cavity, the teeth and the throat.
In addition to cleaning teeth to remove dental coatings (so-called "dental plaque"), the function of oral and dental hygiene preparations is to stop the formation of tartar and to prevent dental disorders, such as caries and periodontosis, and also to eliminate halitosis.
A central problem is the removal of dental coatings. Measures which reduce plaque formation or which remove already formed coatings lead to a reduction in both periodontopathias and caries. Accordingly, one of the objects of the present invention is to provide oral and dental hygiene preparations which are active against the formation of dental coatings.
Plaque formation can be reduced by using microbicidal substances in oral and dental hygiene preparations. Examples include chlorhexidine (1,1'-hexamethylene-bis[5-(4-chlorophenyl)-biguanide]) and numerous antibacterially active quaternary ammonium compounds, such as cetyl pyridinium chloride or the quaternary ammonium compounds described in U.S. Pat. No. 3,369,046. Unfortunately, such antimicrobial compounds can quite indiscriminately attack all the microflora in the oral cavity and thus cause or promote disease of the oral cavity. Such microbicides can also cause serious irritation of the mucous membrane. Another disadvantage of most of the quaternary ammonium compounds is that they can discolor the teeth.
Canadian Pat. No. 673,101 describes the use of a variety of quaternary ammonium fluorides to reduce the solubility of dental enamel in acids. Such compounds either disadvantageously have a strong antimicrobial effect, as explained above, or are ineffectual in preventing plaque.
Accordingly, another object of the present invention is to provide substances which, in oral and dental hygiene preparations, are highly effective against the formation of plaque but which show hardly any antimicrobial activity.